An angry mob killed a fellow student at a Pakistani university campus Thursday on accusations that he'd posted blasphemous content online. It was the latest in a series of vigilante attacks over the increasingly contentious issue in the predominantly Muslim country.

Witnesses and local media reported angry students associated with the ruling right-wing political parties in Pakhtunkhwa province used sticks and broken glasses during the attack on Mashal Khan, a journalism student at Abdul Wali Khan University in Mardan.

"The mob later fired at the tortured body of Mashal Khan and attempted to set the dead body on fire" before police stopped them, a witness said, requesting anonymity.

The crowd marched almost casually to the scene and was so large — estimates put it at about 1,000 — that police said they were unable to intervene to save Khan. Police later arrested about 15 people, and the university was closed down as they sought other suspects.

Blasphemy may be punished by death in Pakistan. While no one has been executed, reports suggest about 17 individuals are facing death sentences, while 19 others face life imprisonment.

Travel advisory

The U.S. State Department mentioned the issue in its latest travel advisory for Pakistan on Wednesday. "Sectarian violence remains a serious threat throughout Pakistan, and the government of Pakistan continues to enforce blasphemy laws," the advisory said. "Religious minority communities have been victims of targeted killings and accusations of blasphemy."

FILE - Students chant slogans while holding banners and posters showing Mumtaz Qadri, the killer of Punjab Governor Salman Taseer, during a rally to protest against any attempts to modify blasphemy laws, in Karachi, Pakistan, Jan. 20, 2011. Qadri was eventually executed in prison.

In one high-profile case in January 2011, a police guard killed the governor of Punjab province, Salman Taseer, who had advocated reforms in what he called the country's "ill-conceived" blasphemy laws and had pleaded the case for a Christian mother facing the death penalty on blasphemy charges.

Pakistan's nongovernmental human rights organization says about 60 people accused of blasphemy have been killed in "mob justice." Most of the victims have been Muslims, along with members of minority faiths such as Christians and Ahmadis.

In some cases, Muslims have used blasphemy charges against non-Muslim neighbors for personal benefit. A Muslim kiln owner, for example, raised allegations against a Christian couple in Punjab province in November 2014 after a salary dispute. An angry mob broke their legs and threw them into the kiln where they had worked.

As many as 30 Muslim countries have blasphemy laws, and there are a variety of possible punishments for violations.

No provision for mob justice

Qibla Ayaz, an Islamic scholar and former vice chancellor of Peshawar University, told VOA's Deewa service in a reference to the student's death that sharia, or Islamic law, doesn't allow mob justice.

The U.S. Commission on International Religious Freedom is critical of Pakistan's blasphemy laws, saying there is no clear definition that empowers accusers to decide whether a violation has occurred.

Pakistan has recently also moved to crack down on dissident voices on social media, in particular Facebook. Additionally, several bloggers vanished for a while this year amid widespread speculation they were kidnapped by government intelligence agencies.